Building new speaker cabinets, need specifications
- Thread starter Laricc
- Start date
RTally
Speaker addict
Your best option is as described by sweschler above at #3. Get the specs of the woofer and use software to determine the proper, matched cabinet size and specs.
If you don't want to do that work, you could use the cabinet dimensions (it is the internal volume that is important), but you will also need to know the port dimensions.
Also, you will need to determine the proper crossover to use. You can calculate the crossover frequency based on the driver specs, but to fully optimize the integration between drivers, you need to test, tweak, test, etc. until it meets your satisfaction.
Laricc
Member
I've looked around for the woofer T/S parameters for a while now and haven't found anything on them. I sadly don't own a DATS system or have the supplies necessary to create my own test on hand to get the parameters.
In that case, I may just base around the original cabinet's volume. Despite that, thanks for the insight! (also, the behringer monitors specified their crossover frequency to be at 2 kHz.)
RTally
Speaker addict
As sweschler pointed out, the software is free. All you need is a computer and microphone (and some small parts). Not only would this allow you to determine the TS parameters of drivers, but it can also be used to verify the crossover design and implementation.
The 2kHz crossover frequency is just a start. Unless you know the driver's impedance at that frequency, you cannot determine the precise component values. That is why most crossovers are designed by first calculating nominal values and then testing the crossover to see if it works with the real world components.
It is possible to shotgun speaker building. Sometimes you get lucky. More often than not, the results are not optimum. Building speakers is a learning experience and a lot of that learning comes from reading books and articles on the basics of good speaker design.
SaSi
Seriously Illogical
If you were replicating a sealed enclosure, then exact enclosure size (alignment) would not be critical as the sealed loading of a woofer is very forgiving. For a ported enclosure, things become more critical with - perhaps - most critical being the port dimensions, then the enclosure volume.
Since you are trying to learn here, just aim to build an enclosure as close as possible to the internal volume of the Behringers and use an indentical sized port.
To go down the path of designing it, you need T/S parameters and it's probably impossible to find them for these woofers.
To match the woofers with the tweeters, you need to know the sensitivity of both, so that the overall output is balanced. It's fine for the tweeters to be more sensitive than the woofers - a small resistor in the high pass section of the crossover can fix that. If however the woofers turn out to be more sensitive - something unusual - it's a tough problem to solve. A resistor in series with the woofer is a bad bad idea.
I would recommend you get Vance Dickason's "Loudspeaker design cookbook" and go through it. It has all the information you may need to build entry level to high performance loudspeakers.
I would suggest you focus, for your first build, to make a good enclosure and mount the drivers on it. That by itself is a challenge and a project. You will do many mistakes and learn from them. So, for your first build, don't bother about what material to get and what would be better (and more expensive). Get cheap plywood. I would not recommend mdf as cutting and trimming it creates a lot of nasty dust you should not breath.
In terms of gluing panels together, my preffered method is to do butt joints enforced with wood screws (3-5 per running ft of joint). When all is dry and set, I remove the screws one by one, drill an 8mm hole in place of the screw hole and glue in an 8mm dowel. After it's trimmed and sanded, the panels can either be pained or veneered.
Since you are trying to learn here, just aim to build an enclosure as close as possible to the internal volume of the Behringers and use an indentical sized port.
To go down the path of designing it, you need T/S parameters and it's probably impossible to find them for these woofers.
To match the woofers with the tweeters, you need to know the sensitivity of both, so that the overall output is balanced. It's fine for the tweeters to be more sensitive than the woofers - a small resistor in the high pass section of the crossover can fix that. If however the woofers turn out to be more sensitive - something unusual - it's a tough problem to solve. A resistor in series with the woofer is a bad bad idea.
I would recommend you get Vance Dickason's "Loudspeaker design cookbook" and go through it. It has all the information you may need to build entry level to high performance loudspeakers.
I would suggest you focus, for your first build, to make a good enclosure and mount the drivers on it. That by itself is a challenge and a project. You will do many mistakes and learn from them. So, for your first build, don't bother about what material to get and what would be better (and more expensive). Get cheap plywood. I would not recommend mdf as cutting and trimming it creates a lot of nasty dust you should not breath.
In terms of gluing panels together, my preffered method is to do butt joints enforced with wood screws (3-5 per running ft of joint). When all is dry and set, I remove the screws one by one, drill an 8mm hole in place of the screw hole and glue in an 8mm dowel. After it's trimmed and sanded, the panels can either be pained or veneered.
bowtie427ss
Lunatic Member
And that's entirely possible as the woofers come from a powered monitor using an active 4th order LR network.
For those who care to do it right, THIS is the way.
Did I miss something between these two posts?I finally got time to test out the speakers.
These were the T/S parameters I got from 2 tests.